February 21, 2013, 3:23 PM — Twitter has implemented DMARC, a standard for preventing email spoofing, in order to make it harder for attackers to send phishing emails that appear to come from twitter.com addresses.
Twitter users are constantly targeted in phishing attacks that try to pass rogue emails as official communications from the company. These phishing emails direct users to fake Twitter websites in order to steal their login credentials.
"Earlier this month, we began using a new technology called DMARC that makes it extremely unlikely that most of our users will see any email pretending to be from a Twitter.com address. DMARC is a relatively new security protocol created by a group of organizations to help reduce the potential for email-based abuse," said Josh Aberant, Twitter's postmaster, Thursday in a blog post.
DMARC, short for "Domain-based Message Authentication, Reporting & Conformance," is a standard for implementing the SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) email message validation and authentication systems.
The technologies can be used to verify that an email with a sender address of, for example, twitter.com actually came from servers authorized to send email on behalf of twitter.com. The goal of DMARC is to achieve a uniform implementation of these systems among the top email services providers and other companies that would benefit from email validation.
DMARC is supported by all four major email providers -- Google (Gmail), Microsoft (Outlook.com/Hotmail), Yahoo (Yahoo Mail) and AOL. It has also been implemented by services like Facebook, PayPal, Amazon and now Twitter.
While Twitter's support for DMARC will help email providers block messages with forged @twitter.com addresses from reaching the inboxes of many users, it won't prevent phishing emails that masquerade as Twitter communications but have non-twitter.com sender addresses. This means that users should remain vigilant and scrutinize all details of emails received from Twitter before acting on their instructions.
DMARC celebrated its one-year anniversary earlier this month, but according to DMARC.org, the industry group that oversees the standard's development and adoption, it already helps protect 60% of the world's email boxes from spam and phishing. More than 325 million spoofed messages were rejected in November and December 2012 because leading email providers and email senders implemented DMARC, the group said on its website.